The Supremacy Clause
Under the Supremacy Clause in the United States’ Constitution, the Constitution and federal laws are “the supreme Law of the Land; and the Judges in every State shall be bound thereby ….” U.S. Const. Art. VI, cl. 2. The Supremacy Clause comes into play when federal interests conflict with state interests, in which case, federal law displaces state law. In other words, under the Supremacy Clause, federal law preempts contrary state law. Thus, “it has long been settled that state laws that conflict with federal law are ‘without effect.’” Mut. Pharm. Co. v. Bartlett, 570 U.S. 472, 479–80 (2013).
The question in a preemption case is whether state law is preempted by a federal statute. “The Supremacy Clause provides a clear rule that federal law ‘shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.’” Arizona v. United States, 567 U.S. 387, 399 (2012) (quoting U.S. Const., Art. VI, cl. 2). “Under this principle, Congress has the power to preempt state law.” Id. (citations omitted).
Determining whether a federal statute preempts a state statute, requires examining congressional intent, that is whether Congress, in enacting the federal statute, intended to exercise its constitutionally delegated authority to set aside the laws of a state. If so, the Supremacy Clause requires the court to follow federal, not state, law. Through the Supremacy Clause, state laws may be preempted in various ways. For example, a federal law may contain a provision that specifically states it preempts any state law on the same matter. “There is no doubt that Congress may withdraw specified powers from the States by enacting a statute containing an express preemption provision.” Arizona, 567 U.S. at 399. However, “[s]tate law must also give way to federal law in at least two other circumstances.” Id.
Field Preemption
“First, the States are precluded from regulating conduct in a field that Congress, acting within its proper authority, has determined must be regulated by its exclusive governance.” Arizona, 567 U.S. at 399 (citation omitted). “The intent to displace state law altogether can be inferred from a framework of regulation ‘so pervasive … that Congress left no room for the States to supplement it’ or where there is a ‘federal interest … so dominant that the federal system will be assumed to preclude enforcement of state laws on the same subject.’” Id. (quotation omitted).
Conflict Preemption
“Second, state laws are preempted when they conflict with federal law.” Arizona, 567 U.S. at 399. “This includes cases where ‘compliance with both federal and state regulations is a physical impossibility,’ and those instances where the challenged state law ‘stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress.’” Id. (quotation omitted). “In preemption analysis, courts should assume that ‘the historic police powers of the States’ are not superseded ‘unless that was the clear and manifest purpose of Congress.’” Id. (quotation omitted).